MR imaging in the management before surgery of lobular carcinoma of the breast: correlation with pathology.

OBJECTIVE: Our objective was to investigate the use of MR imaging in preoperative staging and characterization of lobular carcinoma.

MATERIALS AND METHODS: MR imaging studies and mammographic studies in 20 patients with infiltrating lobular carcinoma were evaluated and correlated with pathology findings on serially sectioned tissue. The MR images and mammograms were reviewed retrospectively by three independent examiners unaware of the clinical, imaging, and pathology findings.

RESULTS: The extent of disease found pathologically correlated with that predicted by MR imaging studies in 85% of patients, compared with a 32% correlation (p < .0001) with mammographic studies. Interobserver agreement on lesion morphology and extent of disease was higher for MR imaging (91% and 100%, respectively) than for mammography (64% and 91%, respectively). The retrospective MR readings did not differ from the prospective reports. No false-positive lymphadenopathy was interpreted on MR imaging. Lymph nodes having metastatic lobular carcinoma on the pathology examination were missed on MR imaging in four patients.

CONCLUSION: MR imaging is significantly more accurate than mammography in determining the extent of disease and characterizing the morphology of infiltrating lobular carcinoma. MR imaging may play a role in preoperative planning, especially when breast conservation is being considered.